Handle Network olso events that do not specify network_type and suchlike

Author: stevekeay

python/understack-workflows/understack_workflows/oslo_event/neutron_network.py

@@ -34,9 +34,9 @@ def from_event_dict(cls, data: dict) -> Self:
             network["name"],
             UUID(network["project_id"]),
             bool(network["router:external"]),
-            network["provider:network_type"],
-            network["provider:physical_network"],
-            network["provider:segmentation_id"],
+            network.get("provider:network_type"),
+            network.get("provider:physical_network"),
+            network.get("provider:segmentation_id"),
         )